Hello, I have found that sage finds a non-zero intersection between polygons when they are parallel but non-intersecting. A reproducible example: ``` # Define parallel polygons. a = Polyhedron([[0, -1, 1], [1, -1, 1], [1, 1, -1]]) b = Polyhedron([[0.0, -0.5, 1.5], [1.0, -0.5, 1.5], [1.0, 1.5, -0.5]])
# Intersection. c = a.intersection(b) # c -> # `A 2-dimensional polyhedron in RDF^3 defined as the convex hull of 3 # vertices (use the .plot() method to plot)` a.plot(fill='green') + b.plot(fill='red') + c.plot(fill='orange') ``` However, when the polygons are made non-parallel the correct answer (zero intersection) is found. ``` # Define parallel polygons. a = Polyhedron([[0, -1, 1], [1, -1, 1], [1, 1, -1]]) b = Polyhedron([[0.0, -0.15, 1.5], [1.0, -0.5, 1.5], [1.0, 1.5, -0.5]]) # Intersection. c = a.intersection(b) # c -> # `The empty polyhedron in RDF^3 (use the .plot() method to plot) a.plot(fill='green') + b.plot(fill='red') + c.plot(fill='orange') ``` Noah -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/2db63a27-ff9e-42a2-8003-06b6d071b572n%40googlegroups.com.
